With the continuous enrichment of smart mobile terminal applications, simultaneously performing multitasking has already become a basic function of smart mobile terminals. Although a background of a smart mobile terminal can simultaneously process multiple tasks, what is displayed to a user at the foreground via a screen is usually only one application interface. For example, when the user views a video through the smart mobile terminal, and if the user also wants to interact with other people through an instant messaging application, the user can only switch from a current video playing interface to an instant messaging application interface.
With the continuous upgrading of hardware of the smart mobile phones, a split-screen function starts to appear on the smart mobile terminals. The smart mobile terminals which support the split-screen function can simultaneously display a plurality of running application interfaces on one screen, which is convenient for the operation of the user.
However, the related smart mobile terminals still perform volume control uniformly on a plurality of applications displayed on the screen under the split-screen function, the user demand of separately performing volume control on the designated applications cannot be satisfied, and conflicts between sounds of the plurality of applications are easily caused.